In various automatic machines, it is necessary for a pallet or assembling table to be movable to any position and perfectly stopped in a predetermined position.
Electric motors or fluid cylinder motors are mostly used to accomplish movement but particularly with such conventional means it has been difficult to precisely stop the pallet or assembling table in a predetermined position.
The present invention eliminates such defects as are mentioned above and is so formed that a pallet on which a work, tool or work device is mounted is movable in a noncontacting state and is precisely stoppable in a predetermined position.
An object of the present invention is to provide an air film or cushion between the pallet and a base supporting the pallet thereby enabling frictionless non-contacting sliding movement of the pallet.
As a result, wearing of the sliding surface can be entirely eliminated and the sliding surface does not require lubrication. Further, the force required to slide the pallet may be so small that, for example, small high precision pulse motors can be used and the device can be made small and cheap. The pallet can be slid to a predetermined position, perfectly stopped by actuating a clamping device and maintained in a stopping state.
Further, in the present invention, a vacuum mechanism is adopted for the above mentioned clamping device. The vacuum mechanism is different from the conventional suction devices made of a flexible member and is so formed that the vacuum area may be larger enabling the suction of metal parts to each other so that such parts cannot be deviated from each other and cannot be easily moved with an applied external force.
The above mentioned conventional vacuum mechanisms, using a mere suction device requires an advancing and returning mechanism, are difficult to manufacture, is expensive and is difficult to maintain in a perfectly stationary state because the suction device is flexible. The present invention has as its other objects the provision of a system which overcomes such defects.